Search results for "Muscle activation"
showing 10 items of 53 documents
Kinematics and electromyographic activity of horse riders during various cross-country jumps in equestrian
2019
International audience; The objective of this study was to identify the key biomechanical patterns (functional muscles and kinematics) of amateur horse riders during various cross-country jumps in equestrian. Eleven riders first performed a control condition that corresponded to jumps over three different obstacles (log wall, brush and tree trunk) before jumping over the same three obstacles in a cross-country course. 3D Kinematics and electromyographic (EMG) activity was synchronously collected which included seven muscles of the riders back, lower and upper limbs. Maximum voluntary isometric strength of knee extensors was also measured before and immediately after the race to investigate …
Attentional Focus and Grip Width Influences on Bench Press Resistance Training.
2018
This study evaluated the influence of different attentional foci for varied grip widths in the bench press. Eighteen resistance-trained men were familiarized with the procedure and performed a one-repetition maximum (1RM) test during Session 1. In Session 2, they used three different standardized grip widths (100%, 150%, and 200% of biacromial width distance) in random order at 50% of 1RM while also engaged in three different attention focus conditions (external focus on the bench press, internal focus on pectoralis major muscles, and internal focus on triceps brachii muscles). Surface electromyography (EMG) signals were recorded from the triceps brachii and pectoralis major, and peak EMG …
Changes in biomechanics of skiing at maximal velocity caused by simulated 20 km skiing race using V2 skating technique
2017
This study investigated how the fatigue caused by a 20 km simulated skating cross-country skiing race on snow affects the final spurt performance from a biomechanical perspective. Subjects performed a 100 meter maximal skiing trial before and at the end of the simulated race. Cycle characteristics, ground reaction forces from skis and poles, and muscle activity from eight muscles were recorded during each trial. Results showed that subjects were in a fatigued state after the simulated race manifested by 11.6% lower skiing speed (P < 0.01). The lower skiing speed was related to an 8.0% decrease in cycle rate (P < 0.01) whereas cycle length was slightly decreased (tendency). In temporal patte…
Core muscle activation during dynamic upper limb exercises in women.
2012
Although several everyday functions and sporting activities demand controlled use of the abdominal and back muscles while working with the upper limbs, the activity of core muscles during dynamic upper limb exercises in the standing position has not been studied extensively. The purpose of this cross-sectional study was to examine abdominal and back muscle activity during dynamic upper limb exercises while standing and to evaluate whether dynamic exercises are appropriate for strengthening muscles. The activation of the rectus abdominis, obliquus externus abdominis, longissimus, and multifidus muscles during dynamic bilateral or unilateral shoulder exercises with or without fixation of the …
Universal spectral profile and dynamic evolution of muscle activation: A hallmark of muscle type and physiological state
2020
The skeletal muscle is an integrated multicomponent system with complex dynamics of continuous myoelectrical activation of various muscle types across time scales to facilitate muscle coordination among units and adaptation to physiological states. To understand the multiscale dynamics of neuromuscular activity, we investigated spectral characteristics of different muscle types across time scales and their evolution with physiological states. We hypothesized that each muscle type is characterized by a specific spectral profile, reflecting muscle composition and function, that remains invariant over time scales and is universal across subjects. Furthermore, we hypothesized that the myoelectr…
Compression Garments in Sport
2019
Abstract In this chapter we summarize the main scientific information regarding the applications of compression garments in sports. This chapter covers the discussion from the clinical compression’s application in patients to how its use has been extended to sport. In addition, the composition and different kinds of textiles are considered regarding the level of compression and methodologies/standards for its classification. The chapter is organized in sections considering the effects of compression garments on physiological, psychological, strength, power, endurance, and muscle activation parameters, and ends with indications of future research directions and methodological aspects regardi…
Revealing the unique features of each individual’s muscle activation signatures
2020
AbstractThere is growing evidence that each individual has unique movement patterns, or signatures. The exact origin of these movement signatures however, remains unknown. We developed an approach that can identify individual muscle activation signatures during two locomotor tasks (walking and pedalling). A linear Support Vector Machine was used to classify 78 participants based on their electromyographic (EMG) patterns measured on eight lower limb muscles. To provide insight into decision making by the machine learning classification model, a Layer-wise Relevance Propagation (LRP) approach was implemented. This enabled the model predictions to be decomposed into relevance scores for each i…
Effects of electromyostimulation versus voluntary isometric training on elbow flexor muscle strength.
2007
The purpose of this study was to determine whether 7 weeks of standardized (same number and duration of repetitions, sets and rest strictly identical) electromyostimulation training of the elbow flexor muscles would induce strength gains equivalent to those of voluntary isometric training in isometric, eccentric and concentric contractions. Twenty-five males were randomly assigned to an electromyostimulated group (EMS, n=9), a voluntary isometric group (VOL, n=8), or a control group (CON, n=8). Maximal voluntary isometric, eccentric and concentric strength, electromyographic (EMG) activity of the biceps and triceps brachii muscles, elbow flexor muscle activation (twitch interpolation techni…
Strength athletes are capable to produce greater muscle activation and neural fatigue during high-intensity resistance exercise than nonathletes.
2009
Acute neuromuscular responses to maximum versus forced repetition (FR) knee extension resistance exercises (4 sets of 12 repetitions [reps] with a 2-minute recovery between the sets) were examined in 4 male strength athletes (SAs) and 4 nonathletes. Maximum repetition (MR) sets were performed to voluntary exhaustion (12 repetition maximum [RM]), whereas in the FR sets, the load was greater (8RM) and the set was continued after voluntary fatigue with 4 additional assisted reps. Maximal isometric force and electromyogram (EMG) activity of the knee extensors were measured before and after the exercise, as well as 2 recovery days after the exercise. Electromyogram activity was also measured dur…
Electromyostimulation Training Effects on Neural Drive and Muscle Architecture
2005
GONDIN, J., M., GUETTE, Y. BALLAY, and A. MARTIN. Electromyostimulation Training Effects on Neural Drive and Muscle Architecture. Med. Sci. Sports Exerc., Vol. 37, No. 8, pp. 1291–1299, 2005. Purpose: The purpose of the study was to investigate the effect of 4 and 8 wk of electromyostimulation (EMS) training on both muscular and neural adaptations of the knee extensor muscles. Methods: Twenty males were divided into the electrostimulated group (EG, N 12) and the control group (CG, N 8). The training program consisted of 32 sessions of isometric EMS over an 8-wk period. All subjects were tested at baseline (B) and retested after 4 (WK4) and 8 (WK8) wk of EMS training. The EMG activity and mu…